• Title/Summary/Keyword: environmental geochemistry

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Environmental geochemistry of persistent organic pollutants in the Pearl River Delta

  • Peng Ping'an;Fu Jiamo;Sheng Guoying;Xiao Xianming;zhang Gan;Wang Xinming;Mai Bixian;Ran Rong;Cheng Fanzhong
    • Proceedings of the KSEEG Conference
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    • 2002.04a
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    • pp.8-10
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    • 2002

  • POPs in sediments and soil in the PRD are comparable to or much higher than those reported in other regions. Some sites may be classified as POPs- polluted with high ecological risks. Large-scale land transform in the process of regional urbanization may facilitate the transfer of POPs in the soil to the sedimentary system by enhancing the soil run-off. Urban atmospheric PCBs in PRD are found to be less than some of the North American or European urbans, but PAHs are significantly higher. The center of the PRD has been the major source area of PAHs and organochlorine pesticides in the PRD. The northern part of the PRD serves as a regional sink for the air particulates and affiliated POPs.

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The Mineralogy and Geochemistry of the Uppermost Sediments of the Lake Hovsgol, North Mongolia : It's Implication to the Paleoenvironmental Changes

  • Tumurhuu, D.;Narantsetseg, Ts.;Ouynchimeg, Ts.
    • The Korean Journal of Quaternary Research
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    • v.18 no.2 s.23
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    • pp.3-3
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    • 2004

  • One short core with length of 146cm(HB-107, at coordinates of $N51^{\circ}$11'37.5";$E100^{\circ}$24'45.6", from 229m water depth was subject of the present study. The sub-samples of the core were analyzed for the water contents (WC%), biogenic silica, identification of the main phases, grain size distribution, geochemistry and some physical properties of sediment(Wet density and Magnetic susceptibility) with aims of recording palaeo-environmental changes in Northem Mongolia. The evaluation of the geochemical and mineralogical proxies on palaeo-climated and palaeo-environmental changes are based on comparison to the behvior of biogenic silica through core, as later one had been showed itself, as good indicator of the climate and environmental fluctuation. Age model of the investigating core based on previously C 14 dated core HB105 taken from the central part of the Hobsgol Lake and the result had been published elsewhere. The core consists of two litological varieties : upper diatomaceous silt, lower clay. According to the age model the upper diatomaceous silt formed during the Holocene, lower caly-during the late Pleistocene glacial period. The geochemistry and phase identification analysis on the core samples are resulted in determining main minerals that form the bottom sediments and their geochemistry. The main include quartz, felspar, muscovite, clinochlore, amphibole and carbonate phase(dolomite and calcite). Through the core not only occur the relative quantitative changes of the main phases, but also happen that the carbonate phase completely disappear in diatomaceous silt. This is believed to be related to the lake water salinity changes, which occurred during the trassition period from Pleistocene glacial-to the Holocene interglacial. These abrupt changes of the mineralogy have been clearly traced in geochemistry of sediments, specially in calcium concentration, which is high in lower clay and low in upper diatomaceous silt. That means, geochemistry and mineralogy of the bottom sediments can be used as proxy data on palaeo-climate and palaeo-environmental changes.

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Geochemistry of the Precambrian metamorphic rocks from the central Sobaegsan Massif, Korea (중부소백산육괴 선캠브리아 변성암류의 지구화학적 연구)

  • Song, Yong Sun
    • Economic and Environmental Geology
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    • v.22 no.3
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    • pp.293-300
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    • 1989

  • The basal metamorphic complex of the central Sobaegsan Massif consists of pelitic & psammitic paragneisses, various kinds of granitic gneisses and lesser amounts of amphibolite. The granitic gneisses could be clearly distinguished from the pelitic and psammitic paragneisses on the basis of major-element geochemistry. A number of geochemical plots reveals that granitic gneisses were derived from calc - alkaline igneous rocks.

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Some Aspects of Tungsten Mineralogy and Geochemistry (중석의 광물학적, 지화학적 고찰)

  • Kim, Sahng Yup
    • Economic and Environmental Geology
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    • v.12 no.3
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    • pp.127-146
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    • 1979

  • Though tungsten minerals have been mined for over fifty years in Korea, which has become one of the worlds largest tungsten producers since 1951, knowledge of their mineralogy and geochemistry is somewhat limited to the school of tungsten students. There is a considerable amount of literature throughout the world on the tungsten mineralogy, the geochemical behaviour of tungsten, the nature of tungsten deposits and geological environments for tungsten mineralisation. Commonly known tungsten minerals such as scheelite and wolframite belong to one of two series, the scheelite or the wolframite series, as the primary tungsten minerals. Secondary tungsten minerals are known rather rare, however, some of them plays an important role-of exploration guide in search for tungsten deposits. The geochemistry of tungsten is imperfectly known, and apparently the behaviour of tungsten in geological processes has been the subject of few studies. Recently, some aspects of the fundamental geochemistry of tungsten has been worked out and compiled the data in broad the up to date by many authors. In order to facilitate the better understanding and future exploration of tungsten deposits, an attempt has been made to summarise the existing knowledge of the fundamental geochemistry of tungsten, together with its common geochemical association with various types of tungsten deposits.

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